The speed limit on Picton Road will be returned to 100km/h this week for the first time in four years.
In 2009, Roads and Maritime Services (RMS) reduced the speed limit to 90km/h when it began an extensive series of safety improvements along the road.
The last of the 15 separate projects was completed last Thursday and, following an RMS review, it was decided to return the speed limit to 100km/h.
The speed limit change will begin tomorrow and be completed by Friday.
The $53 million roadworks covered several sections along the stretch of road and included installing concrete medians, realigning curves, widening the road and improving drainage.
Overall, more than 100,000 man hours of work were put in to install 6.5 kilometres of new guard rails and an extra 1.5 kilometres of overtaking lanes in both directions.
Parliamentary Secretary for Transport and Roads Stuart Ayres said the works aimed to make the road safer and improve travel times for motorists.
"The upgrade included 15 individual projects to improve safety and reduce the most common types of crashes including speed-related crashes, head-on crashes, crashes on a wet road surface and crashes from vehicles running off the road," Mr Ayres said.
"Due to the high number of head-on crashes on Picton Road, the safety improvements focused on separating oncoming traffic by installing median barriers."
The works added 10.8 kilometres of concrete or wire-rope median - more than one-third of the road's length.
According to RMS statistics, the roadworks have already reduced the number of crashes and casualties.
In 2010, the first full year of the safety roadworks, the number of crashes recorded was 28. This was a decline on the previous year's figure of 36.
The number of casualties climbed by one in 2010 to 24 but has gradually fallen to 20 in 2012.
Mr Ayres said that now the work was completed, the RMS would monitor the road to gauge its effectiveness and whether further work was needed.
"The NSW government will look at future upgrades to Picton Road from the Mount Ousley Road interchange to the Hume Highway and from the Hume Highway interchange to Argyle Street in Picton," he said.
He said the RMS would continue to monitor traffic and road safety on the route.